Organic Light-Emitting Diode (OLED) has self-luminous characteristic, and when a current is passing through the OLED, organic material in the OLED may emit light. In comparison with a conventional liquid crystal display, OLED display device has a screen with larger viewing angle and can save electrical energy, therefore, OLED display device has incomparable advantages.
An OLED display device may comprise: a base substrate; and a transparent electrode, an organic layer and a metal electrode formed on the inner surface of the base substrate, wherein the organic layer is provided on the transparent electrode, and the metal electrode is provided on the organic layer. In order to increase the light extraction efficiency of the OLED display device, a light extraction structure may be additionally provided in the OLED display device. In the prior art, the light extraction structure may be provided on the outer surface of the base substrate or provided between the base substrate and the organic layer, so that the light extraction efficiency of the OLED display device may be increased through the light extraction structure. In a case of the light extraction structure being provided on the outer surface of the base substrate, the light extraction structure may be scattered particles, Micro Lens Array (MLA) or a rough surface structure, wherein the rough surface structure may be a structure directly formed on the outer surface of the base substrate, the rough surface structure being provided on the outer surface of the base substrate may reduce substrate mode, so that the light extraction efficiency may be increased. In a case of the light extraction structure being provided on the inner surface of the base substrate, the light extraction structure may be scattered particles, a grating structure or a rough surface structure, wherein the rough surface structure may be a structure directly formed on the inner surface of the base substrate, the rough surface structure being provided on the inner surface of the base substrate may reduce substrate mode and organic mode, so that the light extraction efficiency may be increased.
However, above solutions in the prior art just can increase the light extraction efficiency of OLED to some extent, and in practical application, the light extraction efficiency is still low.